spark plug readers, lend me your powers

Some of you may remember I've been having this lingering MPG issue. The summary is I got the bike last year with a stuck open thermostat, no clue how long it had been stuck and got 29mpg. Changed the T-stat and brought the mpg up to 29. F.I.N.A.L.L.Y am getting to changing the plugs hoping their changing will bring up the mpg a bit more...

Here's pics of the first two changes, the two rear ones (haven't got the front two done yet).

Anyway to me they don't look terrible. Let me know what you think. One of the plugs the bent part of the plug has dry white build up on it on the outside and the other looks to have a little deposit right at the tip of the benpt part on the inside right where I'd expect the spark to arc to.

Let me know you prognosis on these plugs so far if you would please.

Sorry for teh crappy pics... my real camera is M.I.A.

Thanks,
Chip

 

The flash is overstating the white some, but it is a white power around that bend. Attached is antoher pic, again a bit crappy, but no flash that may let you see it better. I got the front two plugs changed and they looked pretty much like the "non white" plug from the rear. Threads were wet on them and some carbon but again, didn't seem as bad as I was thinking they'd be.

 

The one with the white stuff doesnt look that bad. The otherone looks fowled. Unles ou got studff on the electrode when removing the plug.

Now I am wondering about your loss of mileage. Share the info please. Your mileage should be arond 45-54 mpg. Not in the 20s

 

As soon as this bad weather lets up I'm going to go fill it up and give it a good ride then check the milage.. I'll be sure to post it up. The one plug was white, hte other three looks black like that one, near identical.

The exhaust now has NO gas smell like it did before, it smelled like straight fuel vapor coming out before, and the reving seems MUCH smoother now as well. I can't wait to get on it and tive it a run.

 

Good deal. Get all the plugs replaced. You may want to drain as much of the fuel you have in the tank out. Run a good tank though there. Post milage. You may want to run an additive through in a second tank. BG, Lucas, Chevron Techron etc. Make sure your injectors arent all gummed up. see if you get a diff. Cheap thing to try.

 

click: Verrill: Plug Color Chart


Bright white ain't right. You need a light to medium brown.

 

The best spark plug reading info I have found is here: Reading Spark Plugs Correctly

Because of unleaded fuel you will not get color on the porcelain. You have to read the plug base and electrode. Most non-racers and street guys read plugs the wrong way. There is no lead in the fuel to give the porcelain color. You have to read the "heat" ring change for proper plug reading.

Plus you need new plugs and the proper shut down to get the real info. You can kind of get a very general idea buy reading plugs like in the previous posts, but that's all. Unless the fuel has some additives (by user) in it you will not see much color on the porcelain. The color on the porcelain from used plugs is an over rich condition cause by choke when cold or a very rich condition at some point and doesn't real burn off after they have been in use for a while.

The porcelain will show detonation/pre-ignition as little specs but not A/F mixture. Unless there is an additive in the fuel to color the plugs.

 

Sometimes plugs don't have to look bad to be bad, I replace mine every winter regardless of what they look like. What scares me is when one doesn't look like the others...

It's hard to use plugs as a diagnostic tool, especially if you leave them in forever. All the additives, and detergents they put in fuel these days means the plugs can look different depending on the brand of fuel you use. There's a lot of phosphorus in some brands and that can cause a white powdery build up on the electrodes. I would avoid the brands that advertise that they put more crap in their fuel to "Protect Your Engine", what that really means is that they water their shit down with inert chemicals so they can make more money. I buy gas for all my vehicles exclusively from one station in my area that has the least amount of additives with the newest underground tanks. Old Fuel storage tanks can get all kinds of horrible stuff in them (like microscopic rust particles that can easily get past a fuel filter), most new gas stations can even monitor the amount of water in their fuel storage tanks in real time.

 

Cadbury light milk chocolate.....looks fine to me.

 

Today I'm going to start riding the bike regularly even though it's still a bit cold out. With my preliminary MPG test I was quite happy with seeing 39.9MPG over the previous 28MPG.

Also you know how that first mark on the 6th gen fuel gauge always disappears pretty fast? From a full fill up where no more gas would fit in the tank at all I was only getting about 9 miles til that first bar disappeared. On my first ride after the plug change I got to around 15 if my memory servers me right.

Once I burn through a full tank I'll post a more accurate number for my MPG with more fuel burned. That 39mpg was only tested with around 30 miles driven, but I just wanted to really see if it had made any improvement at all, not so concerned with an exact number. I feel that it's made a huge improvement and I'm very happy with th result so far.

 

just a thought, don't ever take someone elses word for work that was done on a bike you bought used. Anything that should be changed as per a regular maintenance should be checked by yourself to verify that it is correct. When I purchasede my 2000 last year with 18K on th speed, the PO ensured me that the plugs were done and the valves were checked the last season. Couldn't resist checking the plugs for there condition and well guess what. It didn't make me feel too good when I pulled out iridium plugs for a Vtec out of my obviously non Vtec motor, completely different plug numbers, luckily they are the same length, special taper and thread. On a positive note, they all had the identical light brown shade. last good highway cruise, 53 Cdn Mpg.